As widely known in the art, a navigation apparatus is designed to calculate a current position of a vehicle using position information and indicate the current position in a map displayed on a display screen.
Furthermore, the navigation apparatus serves to provide a driver with various kinds of information required in driving, such as a moving direction of a vehicle, a distance to a destination, a current moving speed of a vehicle, a route set by a driver prior to driving and an optimum route leading to a destination.
Nowadays, such navigation apparatuses are mounted on a variety of vehicles and the like, including a ship, an airplane and a motor vehicle, and are extensively used to extract a current position and a moving speed or to determine a moving route thereof.
In particular, the navigation apparatus is adapted to calculate the current position of the corresponding vehicle by receiving radio waves indicative of a latitude, a longitude, an altitude and the like from a plurality of artificial satellites belonging to a GPS (Global Positioning System) and, then, visually display or aurally notify a driver of map information including the current position.
A navigation apparatus mounted on a motor vehicle travelling on a road provides, either visually or aurally, various kinds of information such as the name of the current traveling road, a current vehicle position, a driving route and a level of traffic congestion.
The navigation apparatus for a motor vehicle determines the current vehicle position by receiving radio waves from different GPS satellites and calculating the time difference for the signals to reach the motor vehicle. Then, the navigation apparatus retrieves map data for the relevant area from a database and displays on a display screen thus determined current vehicle position together with map information.
In addition, the navigation apparatus for a motor vehicle calculates a driving distance and a moving azimuth angle using a driving information detector such as a velocity sensor and a gyro sensor and displays on the display screen a driving route extending from a start point to the current vehicle position.
Korean Patent Publication No. 10-0506613B1 discloses a drive guide apparatus for a motor vehicle having a function of picture frame and a method for operating the same.
If a driver selects a picture frame and a photo according to his or her preference, the drive guide apparatus displays a picture frame image with the photo set into the picture frame on a display screen, thus improving a vehicle interior. In case an unexpected situation occurs during the vehicle driving, the drive guide apparatus converts the screen of the picture frame image to a screen of a drive guide image, displaying the drive guide image on the display screen.
However, the drive guide apparatus noted above does nothing but to employ a function of the picture frame in a navigation apparatus. In other words, depending on the user's selection, either of the picture frame image or the drive guide image is merely displayed on the display screen.
Moreover, although the drive guide apparatus is configured to automatically convert the picture frame image to the drive guide image when there is an unexpected driving condition or situation, the criteria for determining the occurrence of an unexpected driving condition or situation are ambiguous. In order to assure an accurate conversion, there is a need for a sophisticatedly designed road/driving condition detector capable of determining the unexpected occurrences. However, this could be costly and undermine the advantages offered by the picture frame function, thereby restricting commercialization and popularization of the apparatus.
More importantly, the key role of a navigation apparatus is to continuously provide drive guide information when driving motor vehicle and to enable a driver to cope with various kinds of unexpected situations in advance, thus assuring safe vehicle driving. Accordingly, it would be useless to provide the drive guide information after unexpected situations have already occurred.
Furthermore, a user ought to select either the picture frame image or the drive guide image, limiting that no drive guide information is available when the picture frame image is displayed. Even if the drive guide image is selected while the picture frame image is displayed on the display screen, a time delay is present when converting the picture frame mode to the drive guide mode and loading map data. This poses a problem in that it is impossible to rapidly and timely provide a user with drive guide information.